Use the interactive map below to check population changes. Zoom in to see where Podocnemis unilfilis is Endangered based on IUCN Red List criteria - A3bd.
This is an extension of Norris et. al. 2019 that includes:
- Stochastic population projections.
- Future impacts to populations caused by human acessibility (hunting and habitat change) and actions that reduce river connectivity.
Overall the adult female population is predicted to decline by 58.3% in the future.
Map
Due to the number of points, the map can become slow to respond when you zoom in. Zoom out to a level showing fewer points and you can pan around the map to find the area of interest. Then zoom in again to check the coloured points.
When you zoom in you will see shaded points. The points follow rivers produced by remote sensing (Free-Flowing Rivers, 2019: https://doi.org/10.1038/s41586-019-1111-9) The points are brown where populations are predicted to decline by 50% or more within 3 generations (42 years). Brown points therefore represent rivers where the species is Endangered, following the IUCN Red List population size reduction criteria - A3bd (https://www.iucnredlist.org/about/faqs).
Summaries
A summary of the map results is presented below. This includes summaries by country and major basin. Results include the size and extent of likely population changes. The column “population change” is the difference in the number of adult females after 3 generations (42 years). This is consistent with the population sze reduction criteria used by the IUCN Red List. The column “River length Endangered”, is the proportion of river length where populations declined by 50% or more, and represents the spatial extent of future changes.
Summary by country.
| Country | Population change | River length Endangered (prop) | River length (km) |
|---|---|---|---|
| Bolivia | -0.576 | 0.70 | 22217 |
| Brazil | -0.626 | 0.74 | 190555 |
| Colombia | -0.483 | 0.63 | 38552 |
| Ecuador | -0.781 | 0.85 | 8302 |
| French Guiana | -0.480 | 0.63 | 3298 |
| Guyana | -0.249 | 0.45 | 7372 |
| Peru | -0.684 | 0.78 | 47363 |
| Suriname | -0.261 | 0.46 | 5756 |
| Venezuela | -0.383 | 0.56 | 30022 |
| Total | 353437 |
Summary by basin.
In the table below “Amazon” includes the Amazon Basin together with the Araguaia-Tocantins Basin in Brazil. “Coastal North” includes the Essequibo Basin.
| Basin | population change | River length Endangered (prop) | River length (km) |
|---|---|---|---|
| Amazon | -0.606 | 0.72 | 280121 |
| Coastal North | -0.339 | 0.52 | 20835 |
| Coastal South | -0.973 | 1.00 | 6467 |
| Orinoco | -0.501 | 0.64 | 46014 |
Summary by major basins and countries.
| Basin | Country | population change | River length Endangered (prop) | river length (km) |
|---|---|---|---|---|
| Amazon | Bolivia | -0.576 | 0.70 | 22217 |
| Amazon | Brazil | -0.616 | 0.73 | 180434 |
| Amazon | Colombia | -0.352 | 0.53 | 18687 |
| Amazon | Ecuador | -0.781 | 0.85 | 8302 |
| Amazon | Guyana | -0.982 | 1.00 | 423 |
| Amazon | Peru | -0.684 | 0.78 | 47363 |
| Amazon | Venezuela | 0.069 | 0.22 | 2695 |
| Coastal North | Brazil | -0.516 | 0.66 | 3653 |
| Coastal North | French Guiana | -0.480 | 0.63 | 3297 |
| Coastal North | Guyana | -0.202 | 0.41 | 6928 |
| Coastal North | Suriname | -0.261 | 0.46 | 5756 |
| Coastal North | Venezuela | -0.590 | 0.72 | 1201 |
| Coastal South | Brazil | -0.973 | 1.00 | 6466 |
| Orinoco | Colombia | -0.606 | 0.72 | 19865 |
| Orinoco | Venezuela | -0.420 | 0.58 | 26126 |
The table values can also be presented graphically. This enables a more comprehensive understanding of the patterns.
